In article ,
(Marratxi) wrote:


"Mark Brader" wrote in message
...
John Alexander:
I agree, the idea of cooling the trains on the tube lines is
ridiculous
until you extract heat from the stations and tunnel system first...

Any sort of air-conditioning, to provide effective relief, would have
to work no matter whether the train was on a surface, subsurface, or
deep tube section. Therefore it would be necessary to air-condition
the trains *as well* as applying measures to extract heat from the
tunnels and stations.

What is the problem with having a heat pump to suck heat out of a
deep
tube platform to a liquid (water?) and then to pump the liquid to
the
surface and chill the liquid there for return to the platform?

As someone else said, it's just a matter of money. You either need to
do something like that, or you need to move enough additional air
through
the tunnels and stations to ameliorate the heat buildup. The Channel
Tunnel has a cold-water pipe running through each bore to absorb heat
from the trains; the subway systems in New York and Toronto, on the
other hand, without the deep and narrow tunnels that London has, run
air-conditioned trains and let normal air circulation deal with the
heat.

Incidentally, a new air-conditioning system http://www.enwave.com
is now coming into use for major downtown buildings here in Toronto,
taking advantage of our location on Lake Ontario. Heat from these
buildings is transferred into water being drawn from the lake for the
city's drinking water system; the drinking water won't get
significantly
warmer than it now does in summer, because the water used for this
purpose is coming from a new feed deeper in the lake where the temp-
erature is always 4 Celsius (at which water is densest).
Unfortunately,
London doesn't have a Great Lake next to it...
--
Mark Brader

I believe there is a solution, its a bit Heath-Robinson but consists of
a
large tanker wagon, filled with water, pulled behind each train. As the
train goes through the tunnel a very fine but copious spray of water is
pumped out behind the train. This will absorb heat from the air and
reduce
the temperature. I claim the prize !!!
Cheerz,
( © ) Baz



but the heat would still remain somewhere, even if absorbed into the water
droplets. It's just like the cooling effect of a fan, it doesn't actually
cool a room in a real sense, unless it expels the hot air outside the
room. Perhaps there could be another wagon following that to collect the
warm water for disposal at the end of the tunnel :-)

Roger
(my reader sometimes loses mail/newsgroup messages
- if you think you should have had a reply/comment,
please e-mail me again. Ta!)

wrote in message
...
Heavy snippage !!



but the heat would still remain somewhere, even if absorbed into the water
droplets. It's just like the cooling effect of a fan, it doesn't actually
cool a room in a real sense, unless it expels the hot air outside the
room. Perhaps there could be another wagon following that to collect the
warm water for disposal at the end of the tunnel :-)

Roger

Tfl already claim (as mentioned earlier in this thread) to pump millions of
litres of water a day out of the system, this would be just a little more !!
Cheerz,
Baz